package com.zkingsoft.plugin.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 
 * @author 
 * @createTime 2014.08.30
 */
public class RandomValidateCode {

    public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";//放到session中的key
    private Random random = new Random();
    //private String randString = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";//随机产生的字符串
    private String randString = "0123456789";
    private int width = 95;//图片
    private int height = 30;//图片
    private int lineSize = 40;//干扰线数
    private int stringNum = 4;//随机产生字符数量

    /*
     * 获得字体
     */
    private Font getFont() {

        return new Font("Fixedsys", Font.CENTER_BASELINE, 24);
    }

    /*
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {

        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * 生成随机图片
     */
    public void getRandcode(HttpServletRequest request, HttpServletResponse response) {

        HttpSession session = request.getSession();
        //BufferedImage类是具有缓冲区的ImageImage类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();//产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 24));
        g.setColor(getRandColor(110, 133));
        //绘制干扰
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        //绘制随机字符
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) {
            randomString = drowString(g, randomString, i);
        }
        session.removeAttribute(RANDOMCODEKEY);
        session.setAttribute(RANDOMCODEKEY, randomString);
        g.dispose();
        try {
            OutputStream out = response.getOutputStream();

            ImageIO.write(image, "JPEG", out);//将内存中的图片过流动形式输出到客户
            out.flush();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    /*
     * 绘制字符
     */
    private String drowString(Graphics g, String randomString, int i) {

        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
        String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
        randomString += rand;
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(rand, 13 * i, 16);
        return randomString;
    }

    /*
     * 绘制干扰
     */
    private void drowLine(Graphics g) {

        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /*
     * 获取随机的字
     */
    public String getRandomString(int num) {

        return String.valueOf(randString.charAt(num));
    }
}